The "Introduced" part, does that refer to when the NPC/character was first introduced at all, or as a Chaos Lord? I'm curious because it says Alteon was introduced during September 2013 (as a Chaos Lord) but his NPC has been in-game since either the Beta testing or early 2009…

Through the madness we find, loyalty is no match for power.
Say goodbye to your life, left to rot in your darkest hour.
Prayers won't save you now… as long as you're mine.

Judging from information added to the previous tabs, I think the First Introduced section means when the NPC was actually revealed to be a Chaos Lord. It was never confirmed that Alteon would be a Chaos Lord until the Chaos Swordhaven Saga!

The objective tends to be what the Chaos Lord wants more than anything, since before they were Chaotic and most probably allowed them to actually become a Chaos Lord. The way I see it is that Vath HAD to release the Rock Roc as his Chaos Beast as part of being a Chaos Lord, but isn't his main objective. Same goes for Escherion collecting the Runix Cube. However saying this, I genuinely don't know, so I'll have to do some more research.